Automatic tube cutoff



July 27, 1943. c. SHIPPY AUTOMATIC TUBE CUTOFE 4 Sheets-Sheet 1 Q 2 m R fifi a m w w 3 h a l; U .m a. i a w! u w o a n 4 Sheets-Sheet 2 3nventor attorneys 4/ A4 LL/YLL/ L/ J ly 21, 1943 L. c. HIPPY 2,325,431

AUTOMAT I G TUBE CUTOFF Filed May 18, 1942 4 Sheets-Sheet 3 I P I A I 3 It 5 Snventor 60 (2 S'ZZZZv Uy I I 1' I attornegs y 1943- L. c. SHIPPY AUTOMATIC TUBE CUTOFF' Filed May 18, 1942 4 Sheets-Sheet 4 Zmnentof ('60 6. 57112170] Patented July 27, 1943 r UNITED srATEs 1 PATENT OFFICE- l Auroirwr i z 'ifl a our OFF; it it Q eral Motors Corporation,

poration of Delaware v 7 Application Moylfi, 2, Serial No. 443,435

7 5 Claims, (01. 164 -48) This invention relatesto flying shear or auto matic cutoiT machines arranged to Operate on Continuously traveling stock to cut the same to given length during forward travel.

on fiat sided hollow tubing by incorporating a reoiprccatory knife designed to' first pierce the tubing and then cut through the walls in an outward direction so as to avoid inward collapse andtube deformation together witha pair of retract'ible tube supporting clamps or split dies to buck the wall during the severing operation and thereafter to open apart out of interference to the progress of severed tube ends through the die. I

A further object of the invention is to provide a reciprocable knife carriage actuated in the forward direction'by fluid pressure under control of.

a valve which is triggered by the advance of the tubing to a predetermined point andis reset by carriage travel tclits forward limit. By cycling carriagefactuation in relation to the rate of tube travel the length to'which the tubing is out can be varied and such controlls conveniently ali- -for led by mounting the valve triggering mocha anism for adjustment torse'lective spaced relation with the point of knife operation. Operation of the knife is also by fluid pressure under control of a valve actuated at a given intermediate point in the forward travelofthe carriage.

Simultaneously with knife projection the re-!' tractible tube clamps are brought into. actionand with the retraction of-the knife after the severing operation the tube clamps are allowed. to open prior to return travel of the'car riagei the retraction of the split clampsxthe With severed tube ends, especiallyif theyare burred,

do not jam in the die but thelength of tubecut 7 oil drops from the machine and the end of the. oncoming 'tuhe travels forward as the carriage moves back until the advancing tube end strikes 7 the trigger and again cycles the cutoff operations The structure of the machine and its operation will he better understood upon reierenceto-the accompanying drawings whereinFigures 1 and? are a side elevation and a top p View, TGSP tively, of

3 -4-5 of Figure 1; Figure 4 is a longit dinal sem th cutoff machine; Figure 3 isan enlarged transverse sectional: view taken ongline clamps 6-6.

Detroit, Mioh., a corstock suppliedin rolls. The-flat stock unwound from thespool is fed through shaping apparatus, is scaled and straightened and, then cut'to predeterminedlen ths. i a r As the tubostock, indicated in the drawin a L comes from the straightening machine it passes through an anertured die head of the reciprocating knife carriageofthe cutoff machine: This/head may consist of'a centrally aportured cross bar 2 which, as best seen in Figures 4 and 5, hassecured thereto a die block 3 having a removable closure plate 4 and supporting a stationary die 5 and slldably mounted split die In the space between the dies'S andB-S is a reoiprocable tubecutofi knife blade 1. The upper edge of the knife blade. .is recessed to substantially w-shapaas best seen in Figures initiate the out into'the tube and from which piercingpointdlvergea pair of shearing edges which during the upward'proiection of the knife cut; through the wall of, the tube in an outward direction. The shearing forcebeing exerted in an outward direction eliminates collapse of the tube walls, the tube; walls being bucked by the dies on both sides of the knife,

y'lhe split die is located on the exit side of the shearing head and opens to avoid interference to passage of the tube after the shearing operation. Thus the laterally separable clamp dies 6-6 ea h ha pivoted hereto a stud 8 p jectin u wardly through the wall of the die block 3 and a r inga nut co-seat an expansion spring a. The outer faces of the clamps are formed with com or we e s rfaces for s'lidable encasement with 'corresponding-wedgesurfaces at the upper ends of the spaced arms of-a -U-shaped slider I ii.

This slider 1071s reed pwardly by a pair of coiled compression springs which bear against lateral ears: 'lzon the slidoand surround verof the compression springs H slides the cam:

ming surfaces on one another and contracts the split die 6-6 against the flat walls of the'tubel On the return of the knife the ledge [4 picks up the slider and allows the spring loaded split clamps 6-6 to be retracted. Return of the parts is effected upon release of air pressure on the piston I6 and under influence of" a pair of 'tensioned coil springs I8, which at their upper ends engage outwardly extending arms on the connecting rod structure and at their lower ends are anchored to pins and are housed within dependent tubes l9 on the cross bar of the slidable carriage, This cross bar 20 which preferably is formed integral With the piston cylinder I1 is'sus: pended by a pair of posts 2| from the cross bar 22." Upwardly projecting posts '23 on the cross bar 22 are joinedto-the opposite ends of the die supporting cross bar 2.

The main supporting cross bar-22 of the knife carriage is formed with hearing heads slidable on a pair of ways or bars 24 mounted at opposite ends in standards or supporting brackets 25 projecting upwardly from the bed plate 26 of the machine. Also mounted on the slide bars 24 near the tube entrance end of the machine are the outwardly extending arms 2'! for the air cylinder 28. Slidable within the cylinder 28 is'a piston '29 whose forward movement is transmitted to the knife carriage by connecting linkage 3Q. Retrac- 7 tion of the carriage is accomplished through a pair of tensionable coiled springstll connected at their forward ends to the carriage and rearwardly enclosed by and-joined to the tubes 32 which are carried by'the cylinder supporting armsZ'lf- 577 V 1 losing the head of the cylinder 23 is a valve body 43 which, as best seen in Figures 4 and ll, contains aslidable valve 44!. At one end the valve 44 seats over a port 45 leadingfrom a source of air under pressure. 'At its opposite end it seats over a port 45 which vents to atmosphere. The intermediate chamber of the valve body-43 communicateswith the piston cylinder through either of two ports 41 and 48. one-way check valve 59 while theport 41 is ar ran'gedto receive a projecting Stud 53 on the head of the piston 29, In operation when the valve 44 is moved to the left in Figure 11 the vent to atmosphere is closed and air under pressure lifts the check valve il and acts against the head of the piston!!! to move the knife carriage forward. When the valve 44 thereafter is returned to the position shown'in Figure 11 the air under pressure is cut off and the pistcncylinder is vented through the ports 46 and '41, al-

lowing piston return as the springs 3! restore the" knife carriage. Therapidreturn and abrupt stop of the carriage is to allow trapped aairto' act as a cushion and thereafter bleed out to'atmosphere. a

The operating stem for the valve 44 projects through the valve body 43 and is engaged by one The port 48 contains a eliminated by the fit of the projection 55 into the port 41 in the final range of piston return movementq'I'his fit is suchasend of a pivoted lever M which is held in engagement with the valve stem by a coil spring 52. The opposite end of the lever is connected by a link 53 to a crank arm 54 fixed on the end of a rockshaft 55. This rockshaft has its end, adjacent the crank 5d, supported in a bearing or upright post 56 and extends longitudinally of the machine where its opposite end is secured or Welded to a splined sleeve 57 011 which is slidably keyed a collar 53 rotatably mounted in a supporting bearing 59. The bearing 59 is connected to a longitudinally adjustable block 60 'slidably dovetailed on a fixed support 6! and threadedly receiving a screw shaft 82 which projects beyond the end of the machine and carries a hand crank 63. Supported above the block 69 by an upright 64 is a plate 65, which among other things carries a pointer finger 65 movable over a scale Bl on which markings may be placed to indicate the distance from the knife cutoff operation'to which the supporting block 59 is set by the screw 62 and hand crank Also carried by the plate 65 is a funnel-shaped guide 68 to lead the .end of the oncoming tube 5 to the restricted end of the guide where there is located'the trigger release mechanism controlling the operation of the valve 44. This mechanism (see Figure 9) includes a pivoted bell crank 69 having a pad urged by a coil spring it against the end and over the throat of the guide 58. Pivoted in the other arm of the bellcrank 69 is a pawl H normally pressed outwardly by a looped spring 72, for engagement at its end with a bell crank latch 73. A coil spring i4 normally holds the latch in engagement with a stop i5 in position to obstruct swinging movement of a lever 15., The lever i5 is keyed on the upper end of a vertical shaft i'l which at its lower end has projecting therefrom a lever '58 linked by a tie rod l9to a radial arm 8!? fixed on the collar 58. The slidable spline connection between the collar 58 and the shaft 55 accommodates longitudinal adjustment of the parts by the hand crank 63.

In operation when the trigger mechanism is set by thelhand crank 63 for the desired length of tube to be cut off, the end of the tube is directed by the funnel guide 63 into striking en gagementwith the trigger 69 rocking the trigger to trip the latch 73 and release the lever 75. This frees the rockshaft 55 for rotation in a counterclockwise direction (as viewed in Figures 3 and 11). Such movement occurs under influence of the coil spring 85 anchored at one end to the laterally projected tail of a fixed frame bracket and intermediate rockshaft journal 82 and hooked at its other end to one arm of a bell crank 83 clamped to the shaft 55 at an intermediate point. Operation of rockshaft 55 permits the valve 44 for projection of the knife carriage with the traveling tube. The other arm of the bell crank 83 is positioned in the path of a shoe 84 fastened on the knife carriage 22 whereby when the carriage has moved forward a predetermined amount, engagement of the shoe 84 with the bell crank 83 rocks the shaft 55 in a reverse or clockwise, direction, whereby actuation of the valve control linkage at one end of the rockshaft vents the cylinderlii and actuation of linkage at the opposite end of the rockshaft returns the lever 16 to its locked or-latched position. In the return of the lever 76 the spring 14 yields to allow thelatch 'l3 to be deflected until cleared by the lever and similarlythe return of the trigger 69 under the influence of the spring 19 as the stock drops from the machine, is accommodated by depression of the dog II as it moves over and back of the latch 13. 7

At a predetermined intermediate point in the forward travel of the carriage the piston cylinder controlling the cutoff operation receives a shot of air under pressure through the valve body 85 constituting the head of the piston cylinder N. This valve body, as seen in Figure 4, has in the chamber leading'to the piston, a valve 86 which seats on one side over a port 87 communicating with air under pressure and seats on its opposite side over a port 83 leading to atmosphere. Its stem projects from the valve body and is connected to an operating lever 89 biased by a spring 25 to the vented position of the parts. A contact shoe 9! carried by the lever is arranged to engage at a predetermined point with an abutment roller 92 positioned in the path of the shoe whereby to rock the lever 39 and move the valve 36 to close off the atmosphere port 83 and enable air under pressure to raise the piston H3. lhe shoe 9! moves on past the abutment $2 during the continued further movement of the carriage thereby allowing the valve to be restored to cylinder venting position and the knife 1 to be retracted and the split clamps 65 to be separated. Thereafter the return of the carriage is effected by the pull of the springs 35 upon engagement of the shoe 34 with the rock lever 83 controlling the valve 44 in the manner before described. As the carriage moves back the shoe 9| again contacts with the abutment 92 and in order to prevent operation of the knife on the return stroke of the carriage, the abutment roller 92 is mounted on a swinging frame B l having outwardly projecting pins which, as best seen in Figure 3, pivot the lever on a supporting bracket 95. A coil spring 96 normally holds the lever in upright position with its lower end in limiting engagement with the bracket 95 but yields to allow the lever to swing back for the return passage of the shoe 9 l As seen in Figure 4 the bracket 95 is secured to a stationary part of the machine by the set screws 91 which pass through elongate-d openings in the bracket and therebyallow the bracket to beset in selected fore and aft positions in order properly to time knife operation.

I claim: r V

1. In a cutoif machine of the character described, a movable knife carriage, a fluid pressure responsive device operatively connected with the carriage, a valve controlling the response of said device and being fixedly mounted on the machine, spring meansbiasing said valve to active position, latching mechanism operative to hold the valve in inactive position and against its release to the biasing force of' said spring means,

a trigger engageable by the forwardly traveling stock to release the latch, a one-way ratchet trip for transmitting latch releasing movement from thetrigger, means actuated by the travel of the carriage near its forward limit, to restore the valve to inactive position and to cause the latching mechanism to resume its valve latched relation regardless of the then existing trigger position, spring means to cook the trigger and its ratchet trip back into position wherein the trip is conditioned for transmitting releasing movement to the latching mechanism, an adjustable support for the latching mechanism and its trigger as a unit to enableselectiv-evariation of the set distance thereof toward and from the range of carriage travel and thereby regulate the length of stock out off and adjustable connections between the latching mechanism. and the valve accommodating variations in trigger setting.

2. In a cutoif machine of the character described, a knife carriage operating device and means regulating the operation thereof including a power feed controller, a rockshaft having crank arms at opposite ends thereof, an operative connection between said controller and the crank at one end of the rockshaft, a latch operatively connected to the'crank at the opposite end of the rockshaft, a latch release trigger engageable by the forward end'of the traveling stock after a given length has reached beyond the knife carriage and operable thereby to trip the latch and free the rockshaft and a rocker arm fixed to an intermediate portion of the rockshaft inthe path of the traveling carriage near its forward limit and operable thereby to return the rockshaft to latched position.

3. In a cutoff machine of the character described, a knife carriage operating device and means regulating the operation thereof including a power feed controller, a rockshaft operatively I connected at one end to said controller, a latch operatively connected to the opposite end of the rockshaft, a latch release trigger engageable by the forward end of the traveling stock after a given length has reached beyond the knife carriage and operable thereby to trip the latch and free the rockshaft, a lever fixed to the rockshaft in thepath of the traveling carriage near itsv forward limit and operable thereby to return the rockshaft to latched position, means mounting the latch and trigger for adjustment toward and from the carriage operating device for selectively setting the length of stock cut off and a slidable key connection between the latch and the adjacent end of the rockshaft to accommodate said cutoff length adjustment;

4. In a cutoff machine of the character de-. scribed, a movable knife carriage having a head through which is fed the continuously traveling stock, means active after a given length of stock has fed past the head to move the carriage forward with the traveling stock, a stock cutoff knife reciprocably mounted in the head, means to actuate the knifeat a given point in the forward movement of the carriage, a pair of retractible stock supporting clamps arranged for engagement nection between the cams and knife for relieving the cams upon retraction of the knife.

5. In a flying shear machine having a stock guiding head and a reciprocatory knife slidable in the head to cut'through the stock, a pair of stock embracing clamps for cooperation with the knife, spring means normally biasing the clamps open, a reciprocatory clamp closing member having bearing engagement with the clamps to conract the same upon member projection and having lost motion connection with the knife for retraction therewith and spring means active on said member to project the same into clamp wedging relation upon projection of the knife.

LEO C. SHIPPY. 

